/*
 * Copyright 2009-2011 Cedric Priscal
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <jni.h>

#include "SerialPort.h"

#include "android/log.h"
static const char *TAG = "serial_port";
#define LOGI(fmt, args...) __android_log_print(ANDROID_LOG_INFO,  TAG, fmt, ##args)
#define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, TAG, fmt, ##args)
#define LOGE(fmt, args...) __android_log_print(ANDROID_LOG_ERROR, TAG, fmt, ##args)
int fd;
static speed_t getBaudrate(jint baudrate)
{
    switch(baudrate)
    {
    case 0:
        return B0;
    case 50:
        return B50;
    case 75:
        return B75;
    case 110:
        return B110;
    case 134:
        return B134;
    case 150:
        return B150;
    case 200:
        return B200;
    case 300:
        return B300;
    case 600:
        return B600;
    case 1200:
        return B1200;
    case 1800:
        return B1800;
    case 2400:
        return B2400;
    case 4800:
        return B4800;
    case 9600:
        return B9600;
    case 19200:
        return B19200;
    case 38400:
        return B38400;
    case 57600:
        return B57600;
    case 115200:
        return B115200;
    case 230400:
        return B230400;
    case 460800:
        return B460800;
    case 500000:
        return B500000;
    case 576000:
        return B576000;
    case 921600:
        return B921600;
    case 1000000:
        return B1000000;
    case 1152000:
        return B1152000;
    case 1500000:
        return B1500000;
    case 2000000:
        return B2000000;
    case 2500000:
        return B2500000;
    case 3000000:
        return B3000000;
    case 3500000:
        return B3500000;
    case 4000000:
        return B4000000;
    default:
        return -1;
    }
}

/**
* 设置串口数据，校验位,速率，停止位
* @param nBits 类型 int数据位 取值 位7或8
* @param nEvent 类型 char 校验类型 取值N ,E, O,,S
* @param mStop 类型 int 停止位 取值1 或者 2
*/

int set_opt(jint nBits, jchar nEvent, jint nStop)
{
    LOGE("set_opt:nBits=%d,nEvent=%c,nSpeed=%d,nStop=%d", nBits, nEvent, nStop);
    struct termios newtio;
    if(tcgetattr(fd, & newtio) != 0)
    {
        LOGE("setup serial failure");
        return -1;
    }

    bzero( & newtio, sizeof(newtio));
    //c_cflag标志可以定义CLOCAL和CREAD，这将确保该程序不被其他端口控制和信号干扰，同时串口驱动将读取进入的数据。CLOCAL和CREAD通常总是被是能的
    newtio.c_cflag |= CLOCAL | CREAD;

    switch(nBits) //设置数据位数
    {
    case 7:
        newtio.c_cflag &= ~CSIZE;
        newtio.c_cflag |= CS7;
        break;
    case 8:
        newtio.c_cflag &= ~CSIZE;
        newtio.c_cflag |= CS8;
        break;
    default:
        break;
    }

    switch(nEvent) //设置校验位
    {
    case 'O':
        newtio.c_cflag |= PARENB; //enable parity checking
        newtio.c_cflag |= PARODD; //奇校验位
        newtio.c_iflag |= (INPCK | ISTRIP);
        break;
    case 'E':
        newtio.c_cflag |= PARENB; //
        newtio.c_cflag &= ~PARODD; //偶校验位
        newtio.c_iflag |= (INPCK | ISTRIP);
        break;
    case 'N':
        newtio.c_cflag &= ~PARENB; //清除校验位
        break;
    default:
        break;
    }
    switch(nStop) //设置停止位
    {
    case 1:
        newtio.c_cflag &= ~CSTOPB;
        break;
    case 2:
        newtio.c_cflag |= CSTOPB;
        break;
    default:
        // LOGW("nStop:%d,invalid param", nStop);
        break;
    }
    newtio.c_cc[VTIME] = 0;//设置等待时间
    newtio.c_cc[VMIN] = 0;//设置最小接收字符
    tcflush(fd, TCIFLUSH);
    if(tcsetattr(fd, TCSANOW, & newtio) != 0)
    {
        LOGE("options set error");
        return -1;
    }

    LOGE("options set success");
    return 1;
}

/*
 * Class:     android_serialport_SerialPort
 * Method:    open
 * Signature: (Ljava/lang/String;II)Ljava/io/FileDescriptor;
 */
JNIEXPORT jobject JNICALL Java_android_1serialport_1api_SerialPort_open
(JNIEnv *env, jclass thiz, jstring path, jint baudrate,
 jint databits, jint stopbits, jchar parity)
{
    speed_t speed;
    jobject mFileDescriptor;

    /*波特率 */
    {
        speed = getBaudrate(baudrate);
        if (speed == -1)
        {
            /* TODO: throw an exception */
            LOGE("Invalid baudrate");
            return NULL;
        }
    }

    /* Opening device */
    {
        jint flags = 0;
        jboolean iscopy;
        const char *path_utf = (*env)->GetStringUTFChars(env, path, &iscopy);
        LOGD("Opening serial port %s with flags 0x%x", path_utf, O_RDWR | flags);
        fd = open(path_utf, O_RDWR | O_NONBLOCK);
        //fd=fd;
        LOGD("open() fd = %d", fd);
        (*env)->ReleaseStringUTFChars(env, path, path_utf);
        if (fd == -1)
        {
            /* Throw an exception */
            LOGE("Cannot open port");
            /* TODO: throw an exception */
            return NULL;
        }
    }

    /* Configure device */
    {
        struct termios cfg;
        LOGD("Configuring serial port");
        if (tcgetattr(fd, &cfg))
        {
            LOGE("tcgetattr() failed");
            close(fd);
            /* TODO: throw an exception */
            return NULL;
        }

        cfmakeraw(&cfg);
        //设置波特率
        cfsetispeed(&cfg, speed);
        cfsetospeed(&cfg, speed);

        if (tcsetattr(fd, TCSANOW, &cfg))
        {
            LOGE("tcsetattr() failed");
            close(fd);
            /* TODO: throw an exception */
            return NULL;
        }

        //配置校验位 停止位等等
        set_opt(databits, parity, stopbits);
    }

    /* Create a corresponding file descriptor */
    {
        jclass cFileDescriptor = (*env)->FindClass(env, "java/io/FileDescriptor");
        jmethodID iFileDescriptor = (*env)->GetMethodID(env, cFileDescriptor, "<init>", "()V");
        jfieldID descriptorID = (*env)->GetFieldID(env, cFileDescriptor, "descriptor", "I");
        mFileDescriptor = (*env)->NewObject(env, cFileDescriptor, iFileDescriptor);
        (*env)->SetIntField(env, mFileDescriptor, descriptorID, (jint)fd);
    }

    return mFileDescriptor;

}

/*
 * Class:     cedric_serial_SerialPort
 * Method:    close
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_android_1serialport_1api_SerialPort_close
(JNIEnv *env, jobject thiz)
{
    jclass SerialPortClass = (*env)->GetObjectClass(env, thiz);
    jclass FileDescriptorClass = (*env)->FindClass(env, "java/io/FileDescriptor");

    jfieldID mFdID = (*env)->GetFieldID(env, SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
    jfieldID descriptorID = (*env)->GetFieldID(env, FileDescriptorClass, "descriptor", "I");

    jobject mFd = (*env)->GetObjectField(env, thiz, mFdID);
    jint descriptor = (*env)->GetIntField(env, mFd, descriptorID);

    LOGD("close(fd = %d)", descriptor);
    close(descriptor);
}